test: add unit tests

.github/workflows/tests.yaml

@@ -0,0 +1,27 @@
+name: Unit tests
+
+on:
+  push:
+
+jobs:
+  unit-tests:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "20.x"
+
+      - name: Keep npm cache around to speed up installs
+        uses: actions/cache@v4
+        with:
+          path: ~/.npm
+          key: build-${{ hashFiles('**/package-lock.json') }}
+
+      - name: Install dependencies
+        run: npm ci --no-audit
+
+      - name: Run tests
+        run: npm test

ip.spec.ts

@@ -3,8 +3,12 @@ import { it, describe } from "node:test";
 import assert from "node:assert/strict";
 
 void describe("ip()", async (t) => {
-  void it(`should resolve an IPv4 address`, async () =>
-    assert.deepEqual(await ipv4("localhost"), ["127.0.0.1"]));
-  void it(`should resolve an IPv6 address`, async () =>
-    assert.deepEqual(await ipv6("localhost"), ["::1"]));
+  void it(`should resolve an IPv4 address`, async () => {
+    const ips = await ipv4("one.one.one.one");
+    assert.equal(ips.includes("1.1.1.1"), true);
+  });
+  void it(`should resolve an IPv6 address`, async () => {
+    const ips = await ipv6("one.one.one.one");
+    assert.equal(ips.includes("2606:4700:4700::1111"), true);
+  });
 });